A lever-type indicator is a measurement tool that utilizes lever-gear transmission mechanism or lever-spiral transmission mechanism to convert the size change of the probe to the angular displacement change of the pointer, and indicates the correctness of length and size values when applied to measuring geometrical shapes and mutual alignment of pieces.
Currently, a Chinese patent with the publication number CN201622081U discloses a lever indicator transmission apparatus, a probe stick is provided on the indicator body, a probe is provided at the front end of the probe stick, the rear end of the probe stick is hinged to the indicator body via a hinge axis, a front lever is provided on the hinge axis, the front lever is in tight fit with the probe stick, a shift fork is provided at the upper end of the front lever, a pivot is provided on the indicator body, a rear lever is provided on the pivot, reversing pins are provided on rear levers at both sides of the pivot, respectively, the shift fork is engaged with the reversing pin, a nylon shift block is provided at the other end of the rear lever, a rotatable screw is provided on the indicator body, the nylon shift block is engaged with the screw, and a pointer is provided at one end of the screw.
This type of lever indicator does not possess waterproof and dustproof functions, because the probe extends beyond the end portion of the housing and forms a gap at the end portion of the housing. Such a structure may allow foreign matters such as water, dust and oil cutting fluid to enter the interior of the indicator, the interior parts and components within the lever indicator may be polluted, especially in a mechanical workshop environment where cutting fluid is generated, as a result, failure of the lever indicator is more likely to happen and meanwhile the service life of the indicator is reduced.